Elevation of secondary metabolites synthesis in <i>Brassica campestris</i> ssp. <i>chinensis</i> L. via exogenous inoculation of <i>Piriformospora indica</i> with appropriate fertilizer

<div><p>This work evaluated the impact of exogenous soil inoculation of beneficial fungal strain <i>Piriformospora indica</i> on phytochemical changes and the related genes expression of Chinese cabbage (<i>Brassica campestris</i> ssp. <i>chinensis</i> L.) by greenhouse pot experiments. High performance liquid chromatography (HPLC) affirmed that among the different combinations of fungal and organic fertilizer treatments, the phenolic acids and flavonoids were considerably enriched in organic fertilizer and fungi (OP) followed by organic fertilizer, biochar, fungi (OBP) treated plants. The antiradical activity was higher in OP (61.29%) followed by P (60%) and organic fertilizer (OF) (53.84%) inoculated plants which positively correlated with chlorophyll, carotenoids and flavonoids level (P<0.05). Furthermore, results showed that the exogenous application of <i>P</i>. <i>indica</i> significantly (<i>P</i><0.05) enhanced plant growth, as well as stimulating the activation of chlorophyll, carotenoids and other antioxidant related pathways. The RT-qPCR analysis indicated that key <i>FLS</i> gene triggering the synthesis of kaemferol was up-regulated by the inoculation of <i>P</i>. <i>indica</i>. In conclusion, the results revealed that organic fertilizer and <i>P</i>. <i>indica</i> (OP) is the most appropriate combination for improving phytochemical and antiradical properties in Pakchoi.</p></div

Influence of given treatments on chlorophyll and carotenoids contents.

<p>Influence of given treatments on chlorophyll and carotenoids contents.</p

Primers designed for qRT-PCR analysis of flavonoid biosynthesis genes in <i>Brassica campestris ssp</i>. <i>chinensis L</i>.

<p>Primers designed for qRT-PCR analysis of flavonoid biosynthesis genes in <i>Brassica campestris ssp</i>. <i>chinensis L</i>.</p

Quantitative analysis of phenolic compounds in the leaves of <i>Brassica campestris ssp</i>. <i>chinensis L</i>. after treatments.

<p>Quantitative analysis of phenolic compounds in the leaves of <i>Brassica campestris ssp</i>. <i>chinensis L</i>. after treatments.</p

QRT-PCR analysis of the expression levels of the FLS, CHI, ANS, CHS and F3’H genes from flavonoids biosynthesis pathway.

<p>QRT-PCR analysis of the expression levels of the FLS, CHI, ANS, CHS and F3’H genes from flavonoids biosynthesis pathway.</p

Electrophoresis profiles of the flavonoid biosynthesis pathway genes.

<p>Electrophoresis profiles of the flavonoid biosynthesis pathway genes.</p

Influence of different treatments on A) phenolic contents as gallic acid equivalent (GAE) in mg per g of fresh weight (FW) B) Flavonoids as Quercetin equivalent (QE) in μg per g of fresh weight (FW)., C) phenolic acid as caffeic acid equivalent (CAE) in μg per g of fresh weight (FW)., D) Antioxidant activity.

<p>Treatments Control (C), Chemical fertilizer (CF), organic fertilizer (OF), Biochar (B), Organic fertilizer + Biochar (OB), Biochar + Fungi (BP), Organic fertilizer + Fungi (OP), Organic fertilizer + Biochar + Fungi (OBP), Fungi (P).</p

Electrophoresis profile of candidates for housekeeping genes.

<p>Electrophoresis profile of candidates for housekeeping genes.</p

Effect of given treatments on growth of <i>Brassica campestris</i> ssp. <i>chinensis</i> L.

<p>A) Leaf number, B) Shoot fresh weight, C) Shoot dry weight, D) Leaf area. Values are means and bars indicate SDs (<i>n</i> = 8). Columns with different letters indicate significant difference at <i>P</i> < 0.05 (Duncan test). Treatments Control (C), Chemical fertilizer (CF), organic fertilizer (OF), Biochar (B), Organic fertilizer + Biochar (OB), Biochar + Fungi (BP), Organic fertilizer + Fungi (OP), Organic fertilizer + Biochar + Fungi (OBP), Fungi (P).</p

Design of pot experiment used in this study.

<p>Design of pot experiment used in this study.</p